问题
单项选择题
______ evidence that language acquiring ability must be stimulated.
A．It being
B．It is
C．There is
D．There being
答案
参考答案：C
解析： 本题测试同位语从句。that引导的是一个同位语从句，修饰evidence。there is evidence that+同位语从句，可以作为固定形式，意为“有证据表明……”，注意不要选B选项，it is evidence that…就成了it做形式主语的主语从句，与题意不符。